Processing Clay the easy way | The Woodsman Hut | Forums

Hi guys....

I actually went to school in a ceramics program, and can give you some background on making clay.

Clay quality can vary by geography pretty dramatically. It's best to talk to local potters to see what they know about local soil and geologic features. The ingredients of the available clay bodies in your area may be have some impact on the following characteristics:

Brittle/Flexible - Brittle clay can be improved by adding silica (sand) Feldspars and ground/powdered rocks to the clay mixture will add structure.

Volatile to Temperature - Some clay bodies crack at a max temp. Others melt if it gets too hot (to much silica in the body) To allow for a higher temperature fire, remove the feldspar or soda, increase potash.

Porous or Solid - Porous clay bodies are typically fired at a lower temperature, and can be used for different types of filtration. If you want a clay body that will hold water without weaping, it generally must be fired at a higher temp.

Glassy glaze, or Rough - Glazes are made using a combination of silica, ash and other chemicals that add color. A glassy glaze essentially turns turns into liquid form when fired, and requires some adhesive components like Alumina Oxide to bind it to the clay body (can be reproduced by pounding rocks into dust) German potters use a technique called "salt firing" where they toss handfuls of rock salt directly into the kiln at it's apex temperature, which vaporizes and then collects on the clay body creating a clear, glassy glaze.

There's some great videos on Youtube on brickmaking (all the same principles) all the way to making ceramic tools and pottery

http://www.youtube.c.....re=related

feature=related

http://www.shol.com/.....espiel.htm